Here super keyword calls the same data method of its parent class if data_type == 'option' is false.
Check this link for a detailed explanation.
Super keyword in Ruby

Update:

The above code can be re-written as

if data_type == 'option'
options[super.to_i]#options is probably a hash/array here.
else
super
end

When we call super it returns a value after executing it's parent class's data method, lets assume it returned "5", we're converting that to an integer and getting data out of options array. i.e., options[5].